Open Ocean Iron Fertilization for Scientific Study and Carbon Sequestration

The trace element iron has been recently shown to play a critical role in nutrient utilization, phytoplankton growth and therefore the uptake of carbon dioxide from the surface waters of the global ocean. Carbon fixation in the surface waters, via phytoplankton growth, shifts the ocean/atmosphere exchange equilibrium for carbon dioxide. As a result, levels of atmospheric carbon dioxide (a greenhouse gas) and iron flux to the oceans have been linked to climate change (glacial to interglacial transitions). These recent findings have led some to suggest that large scale iron fertilization of the world's oceans may therefore be a feasible strategy for controlling climate. Others speculate that such a strategy could deleteriously alter the ocean ecosystem and still others have calculated that such a strategy would be ineffective in removing sufficient carbon dioxide to produce a sizable and rapid result. Whether iron fertilization has been a viable mechanism controlling climate in the past, and whether it could be useful in the future is a topic of current debate. What is clear from fertilization experiments to date is that they have been effective tools which allowing us to probe the question of the role of iron in controlling phytoplankton growth, nutrient cycling and the flux of carbon from the atmosphere to the deep sea.